A door of a standard modern-day motor vehicle such as described in copending U.S. patent application Ser. No.08/831,974 now U.S. Pat. No.5,876,087 or Ser. No.08/831,981 now U.S. Pat. No.5,836,639 can be equipped with electrically operated or assisted door latches, with electrically powered window operators, and with various sensors and switches for reporting the open or closed position of the door and/or of its window. In the most up-to-date systems all information is transmitted or exchanged via a single data line while the actual power for the various actuators must be supplied through the standard current-carrying positive and negative conductors. Thus at least three conductors must extend between the current source and control circuits mounted in the vehicle body and the various devices--actuators, sensors, and switches--in the actual door.
With a standard pivotal door the multiconductor electrical cable making the necessary connection is simply loosely passed between the vehicle body and the door and flexes somewhat each time the door is opened and closed. Such a system can be counted on to have a very long service life if engineered properly.
With a sliding door, however, a substantially greater problem is present since the door travels often a distance of as much as 1 m between the open and closed positions. As a result it is impossible to simply provide a loop of cable to make the connection, since it would get caught in the slider mechanism or otherwise interfere with operation of the door. Solutions have been proposed to tension the cable and allow it to pull out and retract, but have generally failed. Alternately it is known to provide a plug and socket that fit together in the closed position of the door only, but such a system requires extremely good engineering and leaves the door completely unconnected when it is open.